1. Field of the Invention
The invention pertains to novel silica gels and the method of preparing the silica gels by neutralizing hydroxide ions by electrolysis at a rate whereby silica gel forms.
2. Description of the Prior Art
The prior art processes for forming silica gel are by removal of the hydroxyl ion by acidification with acid solutions. Examples of which are U.S. Pat. Nos. 3,256,068, 3,281,210, 3,325,249, 3,307,906, 3,372,046, and 3,401,017.
Other methods include defluorinating pigmentary silica (U.S. Pat. No. 3,511,605), removing the alkali metal anion with a certain exchange resin (U.S. Pat. No. 3,533,816), burning coarse particles of silica oxide, or vaporizing silicate solutions in an arc (U.S. Pat. Nos. 3,649,189, 3,383,172, and 3,455,718), and electrodialyzing silicates (U.S. Pat. No. 3,668,088).
The art also describes forming chemically pure soluble silicic acid by electrolysis (U.S. Pat. No. 1,132,394), but not silica gels. The art describes formation of pure silica sols by electrolysis of sodium silicate solution between a rotating platinum anode and a flowing mercury cathode from which the sodium produced by electrolysis is continuously removed. This is described in Soluble Silicates, Their Properties and Uses, Vol. 1, Chemistry by James G. Vail, American Chemical Society, Monograph Series-Book Division, Reinhold Publishing Corporation, New York 36, U.S.A. (1952), page 96.
The prior art also describes an electrolytic process for preparing a solution of a highly siliceous ratio from ordinary commercial water glass. [Codd, L. W., British Pat. No. 206,752 (1923), Codd, L. W., U.S. Pat. No. 1,557,491 (1925), Collins, N. L., U.S. Pat. No. 1,562,940 (1925), and Frieth et al, U.S. Pat. No. 1,541,699 (1925)]
None of the references, however, teach or suggest formation of a silica gel, as described herein.